package com.example.demo.study;

import java.sql.Array;
import java.util.HashMap;

public class Study16 {
    public static void main(String[] args) {
        HashMap<String, String> map = new HashMap<>();
        map.put("1", "a");
        map.put("2", "b");
        map.put("3", "c");
        map.put("4", "d");
        for(Object o: map.entrySet()){
            System.out.println(o);
        }
        int [] a = {1,2,3,4,5,6,7,8,9,10};
        int [] arr = new int[10];
        System.out.println(arr.length);
        for (int ar :arr
             ) {
            System.out.println(ar);
        }

        String[] str = new String[10];
        for(String s : str){
            System.out.println(s);
        }

    }
}
